Influence of UV-B Pretreatments on Kinetics of Convective Hot Air Drying and Physical Parameters of Mushrooms (Agaricus bisporus)

Abstract

The present study aimed to investigate the effects of ultraviolet-B (UV-B) pretreatments on selected physical properties (shrinkage, rehydration, color, texture) and drying kinetics and to model the drying kinetics of hot air dried mushrooms using several mathematical models, such as the Henderson–Pabis, logarithmic, two-term, Verma, Wang and Singh, Midilli, and modified Henderson–Pabis models. Results showed that the use of UV-B pretreatment before mushroom drying reduced shrinkage, color changes, firmness, and drying time and increased rehydration and the effective moisture diffusion coefficient. The amount of activation energy increased from 16.55 ± 1.3 kJ/mol (control sample) to 18.27 ± 2.2 kJ/mol (UV-B treated samples for 30 min), 19.72 ± 1.4 kJ/mol (UV-B treated samples for 60 min), and 21.9 ± 1.9 kJ/mol (UV-B treated samples for 90 min). However, increasing the drying temperature increased the shrinkage and firmness of samples. The modified Henderson–Pabis model with the highest correlation coefficient (R2) and lowest root mean square error (RMSE) and chi-square (χ2) showed the best fit for every drying curve, proving to be an excellent tool for the prediction of drying time.